This invention relates to magnetic bubble memories and, more particularly, to a system for purging the contents of such a memory and providing a visual verfication of the purge.
In recent years, magnetic bubble memories have gained in popularity over other non-volatile storage devices for secure data. This is because, unlike magnetic tapes or discs, no fringe field areas exist in magnetic bubble memories that can be analyzed for previously stored data. In a magnetic bubble memory, a single write pass of all data absolutely removes all previous data.
When using a magnetic bubble memory for secure data, it is sometimes desirable to be able to completely erase, or purge, all of the data from the memory. If the built-in writing circuitry were utilized, the problem exists that the system supporting the bubble memory must be running and continue to run for the entire purge period. With a one megabit bubble memory, approximately ten seconds are required to completely rewrite the memory with bogus data. In an emergency situation, this time may not be available.
It is therefore a primary object of the present invention to provide a substantially instantaneous magnetic bubble memory purge system.
It is a further object of this invention to provide such a purge system with an arrangement for indicating that a purge has successfully been performed.